A particle moves in a line so its position at any time in t ≥0 is given by the function s(t)=t²-6t+5,(adsbygoogle = window.adsbygoogle || []).push({});

where s is measured in meres and t is measured in seconds.

a) find the displacement during the first 6 seconds.

All i did was input 0 into the equation solve, then do the same with 6 and subtract the two. I got 0. Is this the right way to do that, os is that too "physics like"?

b)Find avg. velocity during first 6 seconds.

i basically did the same thing with (y2-y1)/(x2-x1) and got 0.

c) Find instantaneous velocity when t=4.

the derivative of the function is 2t-6 so:

s(4)=2(4)-6

=2

d) Find the acceleration of the particle when t=4

the derivative of 2t-6 is 2 so is it 2?

e) At what values does the particle change direction?

I got when t=3 but only by looking at the graph. How do you do this by calculus?

f) Where is the particle when s is a minimum?

again by using the graph

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# Homework Help: Find instantaneous velocity

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